Which tool allows bending a mesh?
It is the Bend Tool, Mesh -&gt; Transform -&gt; Bend

Shortcut Shift-W.

It is documented as operator in the API


  Bend selected items between the 3D cursor and the mouse




The Warp function that used to be on Shift W is from 2.70 replaced by the Bend tool. The Warp Tool is still there, but you have to search for it. In the feature video you can actually hear the commenter telling he is using the Bend Tool.